The main difference between fast charging, slow charging and overcharging of charging pile is the charging speed and power. Slow charge generally uses a lower power current, which takes longer to charge, but does less damage to the battery.
Fast charge uses higher power current and can fully charge the battery in a shorter period of time, but may have some impact on battery life.
Supercharge is a higher power fast charging, which can charge a large amount of electricity to the vehicle in a very short time, and is usually used for rapid recharge of electric vehicles.